Polysulphide polymeric product



POLYSULPHIDE POLYMERIC PRODUCT Filed June 2'?, 1958 ,Dub nbr Josefina 6.(Paric Patented Mar. 31, 1942 y UNITED STATE s PATENT oFFlcE 2,278,127POLYSULPHIDE POLYMERIC PRODUCT Joseph C. Patrick, Morrisville, Pa.,assignor to Thiokol Corporation, Trenton, N. J., a corporation ofDelaware Application June 27,1938, seria1N0.216,oss

2s claims. (c1. 26d-w42) This invention relates to polymers andplastics.

mechanical strength and resistance to rupture,A

and abrasion.

Themeans of attaining these and other objects will appear from thefollowing specication and drawing annexed thereto and forming a partthereof. v

The raw materials of the invention include on the one hand the wellknownsubstance identified as polymerized butadiene which is a polymer ofthe hydrocarbon CH2=CHCH=CH2 and on the other hand substances which maybe dened vas substantially polymers of the unit where R is an organicradical having the skeleton structure work, as, for example, bycompounding with various ingredients including carbon black and otherfilling and strengthening or,r extending ingredients. It has beendiscovered, however, that if the butadiene polymers are incorporatedwith compounds which are substantially polymers of the said unit Rf-S2to s-, the result of this-incorporation is a new compound which can besatisfactorily worked up. Another advantage of the present invention isthat a combination of polymers vof the unit Rf-Sewaand polymerizedbutadiene produces a compound having One object isl to produce syntheticrubber and increased resistance to solvents, ageing, sunlight, heat andabrasion. y

For example, polymerized butadiene is severely deteriorated by theaction of ben'zol, toluol, carbon tetrachloride, aromatic tars and tardistillates, and vegetable andanimal fats, and is substantiallydeteriorated by petroleum solvents, such as gasoline, lubricating oils,etc. By incorporating polymerized butadiene with polymers of the unit-R-Sz tos-1 as herein set forth, and curing the product of theincorporation by heat, cured products are obtained having a satisfactoryresistance to the solvents mentioned, as well as resistance to ageing,sunlight, heat and 5 abrasion.

Again, polymerized butadiene is commonly cured by heating with sulphur,but the cured products "b1oom rather badly, vdue to the migration offree sulphur to the surface of the cured product. If instead of sulphur,a polysulphide polymer, for example a tri, tetra, pentaor hexa-sulphidepolymer is used, together with a vulcanization accelerator, a curedproduct may be obtained free from the phenomenon of fblooming andpossessing marked stability to deteriorating iniluences suchas sunlight,heat combined with oxygen, et cetera. The polysulphide polymer acts as avulcanizing agent. Free sulphur does not migrate to the surface of thecured product, the latter is not subject to the phenomenon of "bloomingand moreover possesses remarkable stability toward deterioratinginiiuences, including heat, oxygen, sunlight et cetera.

There are numerous classes and species of polysulphide polymers, the useof which, incorporated with polymerized butadiene, produce productshaving special advantages. For example, there is a class of polysulphide-polymers having the general formula Then there are the reactionproducts of said [-Rf-Sz-l polymers with compounds having the formula y-where R has the same definition as that given above.

Wherethe primary consideration is the highest possible mechanicalstrength and elasticity; 4it is preferred to'use said [-R-Sz--l ordisulphide polymers for incorporation vwith polymerized butadiene.

ing formula:

Where, however, the primary consideration is resistance to solvents anddeteriorating influunit are preferably used. Here again a wide varietyof such polymers is available and special advantages have beendiscovered to be obtainable by obtained by proceeding in the aboveexample, but omitting the [-R-Sz-l polymer) has far greater resistanceto deteriorating influence such as sunlight, oxygen, ozone and thecombination of atmospheric oxygen and heat.

Another substantial advantage resulting from 'the use of the R-Szandother polysulphide polymers in combination with polymerized butadiene isthe fact that whereas most, if not all,

using certain classes and species of polysulphide of the butaqlenepolymers are extremely renac tory and diicult to Work on ordinary rubberpolymers. For example, if not only freedom machinery, the addition ofeven the small profrom sulphur bloom and resistance to solvents Ortionof the polymer polysulphide very mate and deteriorating influences, butalso a high dep.

rially increases the workability of the resultant gree of elasticity andmechanical strength is de- .red it is recommended to use a polymer Where1 compound. This greatly increased workability is has the Skeletonstructure surprising and could not be predicted from the f -Kindependent properties of the polysulphide polyl mers and polymerizedbutadiene, respectively, be- "T I" cause the polysulphide polymers arethemselves 20 refractory. representing carbon atoms separated by inter-EXMPLE 2 vening structure, e. g., ether linkage or unsatu- Compound A-rated carbon atoms. Parts by weight The use of various classes ofpolysulphide poly-` Rubber-like butadiene polymer 100 mers incorporatedwith polymerized butadiene 5 Soft carbon black 50 and the advantagethereof will be illustrated by Zine oxide 5 reference to the followingtable. The properties Stearic acid 2 represented are those` of compoundscured as Sulphur 2 hereinafter set forth. Mercapto benzothiazole 1 TableI 100 arts f tetra- 100 art f d'.ul 3 arts of tetrablgsggrgge. tyrslglg.sulp ide plolyrner, philde olynir, sulghide polymer, see Example 2,l sccExamples 5 100 parts of poly- 2 parts ol' polymerl00 parts of poly-Compound A and merized butadiene; ized butadiene; menzed butadiene;

see Example 2 see Example 3 see Example 4 Tensile strength: pounds persquare inch. 3,600 1.000 3,100 2,100 4.000 Elongation 600 400 600 550650 Linear swell after exposure to gasoline percent.. l4 3 3 2 13-14Decrease in elongation after the hot kerov sene test perceiit... 25 Nonel0 10-15 Details to serve as a guide in obtaining com- Compound B poundshaving special properties will be illus- Parts by weight trated below.Polymer produced as in Exam le 5 100 EXAMPLE 1 p 4" soft carbon black 5oIncorporation of polymerized butadiene with Zinc oxide 8 a compoundwhich is substantially a polymer of the unit RSz where R is an organicradical having at least two carbon atoms separated by structurecharacterized by the presence of an ether 'or ether-like linkage.

The said polymer is incorporated with polymerized butadiene and othercompounding ingredients on a rubber mixing roll or in a masticator toproduce a product having the follow- Parts by weight Polymerizedbutadiene 100 Polymer produced as in Examples? and 8 5 Carbon black Zincoxide 5 Pine tar 3 Stearic acid 2 Sulphur 2 Benzothiazyl disulphide 1The two mixes are compounded separately. After each has been thoroughlymasticated, a iinal compound is made, using parts by weight of compoundA and 100 parts by weight of Compound B, the two compounds beingthoroughly mixed and masticated'together on the rubber rollers. Thereason for making each of these compounds separately is that ln manycases better dispersion of the pigments is obtained when the aboveprocedure is followed. Both of the compounds were tough and diilcult towork, but when combined a smooth roll was obtained on the mill and theresultant compound had excellenttubing qualities. This blended stock wascured for thirty minutes at a temperature of 298 F. When tested, itstensile strength was 3100 lbs. to the square inch and its elongation was600%. When immersed in gasoline at a temperature of F. for a period often days, the test piece had undergone a linear swell of only 3%,whereas the corresponding Compound A utilizing the butadiene polymeralone had undergone an increase in linear swell of 14%.

When immersed in kerosene for ten days at a temperature of 158 F. itssurface was unaffected and its physical properties were substantiallyunchanged, whereas the corresponding butadiene polymer compounded asshown in A andvcured as above under the same conditions had undergone adecrease of elongation of 50% and the surface was definitely softened.

In CompoundB given above, in which the polysulphide polymer was usedalone, the tensile strength was found to be- 1000 lbs. per square inchand the elongation 400%. When subjected to the above tests, the curedproduct of Compound B underwent in the gasoline a linear swell of 3%,and in the kerosene test underwent about 25% decrease in elongation, andthe tensile strength remained the same. Therefore it is plain that theproperties of the compounds produced as in. Example 2l by incorporatingthe vpolymerized butadiene with thev polysulphide polymer are not themere aggregation of the properties of the respective components andcould not be predicted by the known properties of the said compounds.

EXAMPLE 3 Compound A Parts by weight Polymer produced as in Example 9100 Soft carbon black 60 Zinc oxide '7 Stearic acid 1 Benzothazyldisulphide 1 This compound, whenr mixed on the rubber mill, isrefractory and difficult to process, although the product resultingtherefrom, when cured for fty minutes at 298 F. has valuable propertiesas regards resistance to severe solvents,

such as benzol, toluol, and lacquer solventssuch as esters, alcohols.turpentine, et cetera.

Compound B was made exactly as in the case of Compound A except that twoparts of poly-` The result is surprising, both as to the effect lobtained by the relatively small proportion of the polymerizedbutadiene, as Well as from the fact that the butadiene polymer alone isitself extremely difficult to process. Also a compound of the butadienepolymer alone would be extremely susceptible to the type of solventsenumerated in this case.

EXAMPLE 4 Compound A Parts by weight Polymerized butadiene 100 Carbonblack 40 Zinc oxide 8 Pine tar 3 Stearic acid -2 Sulphur 3 Benzothiazyldisulphide 1 A Compound B was made identical with Compound A exceptinstead of sulphur, three parts of a tetrasulphide polymer. which may bemade by the interaction of sodium tetrasulphide and propylenedichloride, was used. Stock A was difficult t0 compound, being rahertough and nervy. When cured for thirty minutes at 298 F. it showed atensile strength of about 3600 lbs. per square inch and an elongation of600%. At the end of thirty days, definite signs of sulphur bloom couldbe noted on the surface of the sheets of the compound stock and theuncured compound showed blooming in five days.

Compound B worked with extreme ease on the rubber mill, was not toughand showed a very satisfactory absence of nerve When cured for ftyminutes at 298 F; it gave a tensile strength of about 4000 lbs. persquare inch and 650% elongation. When cured sheets from the twocompounds were exposed to a stream of air ata temperature of 70 C.- fortwo weeks, the product of Compound A showed a tensile strength of only3000 lbs. to the square inch and an elongation of 400%, whereas thesheet cured from Compound B showed 3900 lbs. tensile strength and 620%elongation. That is to say, the loss in tensile elongation was verymarkedly less in the case of the two components but also an oxidizingagent and preferably also a vulcanization accelerator and an organicacid. The oxidizing agent may include a metallic oxide, e. g., an oxideof zinc, lead,

. bismuth, arsenic, antimony, etc., an oxidizing salt, e. g., aperborate or chromate or an organic oxidizing agent, e. g., benzoylperoxide or an aromatic mono or poly nitro compound. The vulcanizationor curing accelerator may include benzo thiazyl vdisulphide, tetramethylthiuram disulphide, mercapto benzo thiazole, diphenyl guanidine and.other organic vulcanization accelerators. The organic acid may includestearic acid, benzoic acid and numerous other organic acids. The use ofthese several types of compounding ingredients has been illustrated bythe above examples. y

In view of the numerous classes and species of compounds which aresubstantially polymers of the unit [-R--Sz to s-] it will be necessaryto go into considerable explanation and detail to demonstrate themeaning and scope of said formula and this will now be done.

Polymers of the unlt [-R-Szm s-] may be obtained by at least two routesor reactions, (l) by reaction between an alkaline polysulphide and anorganic compound having at least two carbon atoms and substituentsattached to each of said two carbon atoms and (2) by the oxidation of anorganic compound having at least two carbon atoms and an SH groupattached to each of said carbon atoms.l y

The mechanism of said reactions will now .be described, reference beinghad to the accompanying drawing, in which l Figs. l to 6 show themechanism of the polysulphide reaction.

In the polysulphide reaction an alkaline polysulphide is employed whichmay be derived by the reaction of sulphur with a member of the groupconsisting of alkali and alkaline earth metals, ammonia and amines, e.g., sodium, potassium, lithium, caesium, etc., barium, calcium,strontium, etc., ammonia and ethanolamnes and i'hepolysulphide may be adisulphide, trisulphide, tetra-A form a complex pattern or chain, i. e.,the relatively small molecules of the organic substancev are joinedtogether to form a very large molecule or polymer. 'This joinder takesplace through the medium of the sulphur in the polysulphide. Thissulphur acts as a sort of bridge from one molecule to the next. As aresult, the reaction products have high percentages of sulphur. Theyalso have colloidal properties.

Reaction A (see the drawing) occurs because the Na (sodium) unites withthe X' atom or radical, i. e., splits oi the said X' atom or radica fromthe compound This causes the group i (Nadi) atom attached to anothercarbon atom.

Owing to the capacity of the sodium to unite with the said replaceableysubstituent, the compound produced in Equation A has the remarkableability of uniting with itself, as shown in Equation B. (Fig. 2.)

Moreover, the compound produced as shown in Equation B unites withitself in the same manner and this continues until the size of themolecule is so large that its sluggishness prevents further condensationor self-union. See Fig. 3.

This ability requires the existence of a sodium polysulphide radical (orits equivalent) on one carbon atom and a replaceable substituent onanother carbon atom of the same compound.

If this rule is observed, union of the compound containing said pair ofcarbon atoms to form a compound containing a tetrad or quartet of carbonatoms does not exhaust the reaction because each terminal carbon atom ofthis quartet will also have attached thereto, respectively, areplaceable substituent and a sodium polysulphide radical, so that thequartet or tetrad can form an octad, etcetera.

This permits a building up of a carbon chain in geometrical progressionstarting with a compound containing (butnot necessarily consisting of)two carbon atoms.

The fundamental requirement is that the starting compound shall have atleast two carbon atoms and at least two substituents attached to saidcarbon'atoms, respectively, which substituents are ultimately split off.Reaction of this compound with sodium polysulphide replaces one of thesesubstituents with a sodium polysulphide radical as set forth in EquationA and produces a compound having one of said` substituents onv onecarbon atom and a sodium polysulphide radical on another carbon atom.

'I'he unit of the chain is the' said pair of carbon atoms plus a groupof sulphur atoms, thus:

s l l Il c (Iz-s-s- Il s where the group of sulphur atoms is the tetra?sulphide group. This group may be the disulphide group -S-S-, thetrisulphide group the tetrasulphde group shown, the pentasulphide groupI s ss H Il s s or the hexasulphide group depending upon whether analkaline disulphide, trisulphide, tetrasulphide, pentasulphide orhexasulphide is used. With this explanation the reaction can be regardedfrom the mechanical point of view and it is clearest when so regarded.The said unit can be likened to a unit building block with at least twointerlocking memberson each unit. For example, one of these members mayhave a male thread and the other a female thread. Themale membervon oneunit can then engage the female member on another unit, so as to buildup a chain or complex structure. There must be at least two of suchinterlocking members on each unit. Otherwise the length of the chain islimited to a union of two elements.

Referring now to the diagram, the compound shown as produced in reactionB continues to unite with itself until a long chain is built up havingthe formula shown at C. (Fig. 3.) 'Ihis then loses its X terminal andacquires SH terminals at each end byhydrolysis, as shown in Equations Dand E. At this stage the condensing or polymerizing action of thepolysulphide substantially ceases. (Figs. 4 and 5.)

It is desirable to carry out the above reaction in an alkalinedispersion medium as specifically illustrated in Example 5 below, and toproduce the polymer at the above-mentioned stage in the form of alatex-like liquid from which the poly-v mer may be separated by variousmeans, e. g., coagulation produced by the addition of acid. This latexhas the property of mixing intimately with water without dissolvingtherein and may therefore be washedthoroughly to remove solubleimpurities.

Notwithstanding the large size of the molecule' produced as indicated atE, further increase in size may be caused by employing oxidation,preferably while the product is still in the dispersed form and prior tothe curing step, i. e.. while the polymer is still in the intermediatestage. This may be done by blowing air through the dispersion, providedit is deiinitely alkaline, or by employing any of a number of oxidizingagents effective under alkaline conditions, such as hydrogen peroxide,benzoyl peroxide, sodium, potassium, barium and calcium peroxides,perborates, permanganates, chromates and dichromates, etc. When oxidizedthe polymer shown at E conamara? denses as indicated by Equation F inthe diagram. Alkaline polysulphldes are themselves oxidizing agentsprovided an excess be employed over the equimolecular proportions shownin Equations A to E inclusive.

It is generally desirable to increase the size of the molecule as muchas possible in the intermediate stage, because this in conjunction withthe subsequent curing after incorporation with polymerized butadienetends to develop the desirable qualities of mechanical strength,elasticity, resistance to chemicals and solvents, etc., to the highestdegree.

Proof that the reaction producing the (l) 2 (HS.R.SH) +O=HS.R.S.S.R.SH

where R=C2H4.0.C2H4.

The above dimercapto ether is obtained by reaction BB dichlorethyl etherwith sodium hy'- drosulphflde NaSH.

This continues until a polymer is built up having the formula (3)HS.(RSS) nR.SH

This on further oxidation gives (4) HS. (RSS) 11R.S.S.R(RSS) HS Theabove compound (4) reacts with sulphur to produce a product identicalwith that shown in VEquation F, Fig. 6, in the diagram and converselyThis labile sulphur is of great value in the reaction of the polymerscontaining it, with polymerized butadiene.

In theY formula shown in Equation F, the value of n isso great that theproduct is substantially and practically-a4 polymer of the unit and theproduct reacts as such. For example, three mols of this unit react withtwo mols of sodium suphide according to the following equation:

and the resulting product is identical in all its properties with theproduct produced by oxidation of a polyfunctional mercaptan as shown inEquations 1 to 4 above.

Conversely, the polymer shown in Equation 4 above as produced byoxidation of a polyfunctional mercaptan behaves substantially as apolymer of the unit ant-1 two atoms of and the product obtained isidentical in all its the product shown in Equation F can be partiallydesulphurized to produce a product identical with that shown at (4)above.

The above mercaptan reaction shows that the linkage between theorganic'carbon radicals'is through a sulphur bridge.

(f) X-ray examination shows that the distance between the carbonradicals is equal to the sum of the diameters of two sulphur atoms.

'I'he two sulphur atoms referred to are bound rmly and form the directbridge between-the carbon radicals whereas the remaining sulphur atomsare in labile form and may be removed by a partial desulphurizing actionas already mentioned.

A properties with that shown in Equation F in the diagram. I

This is further proof that the organic radicals in the polymerl i. e.,the carbon radicals, are joined together through a bridge of two sulphuratoms. This bridge is in rm chemical combination, whereas the remainingsulphur atoms in the polysulphide polymer are in labile condition andmay be removed by partial desulphurizing agents, such as alkalinemonosulphides, alkalies including NaOH and KOH and sulphites. Thetri-,tetra, pentaand hexasulphides react with polymerized butadiene and causecuring or vulcanization thereof without the need of any extraneoussulphur.

In the above equations, instead of the tetrasulphides, the di, tri,pentaand hexasulphides similarly react.

The fundamental requirement for the reactions shown in Figs. 1 to 6 ofthe drawing is an organic compound having at least two carbon atoms anda substituent attached to each of said carbon atoms, which substituentis replaceable, i. e., is split off during the reactions whichoccur whensaid'compound is reacted with an alkaline polysulphide.

For the mercaptan reaction it is necessary to have an organic compoundhaving at least two 4carbon atoms and an -SH group attached to each ofsaid carbon atoms, thus action shown in Figs. 1 to 6 are substantiallypolymers of the unit H (is, W]

Compounds produced by the mercaptan route are substantially polymers ofthe unit Polymers of the unit t teme] contain labile sulphur uponremoval of which, as by reaction with reducing or desulphurizing agents,they are converted to polymers of the unit als]

and conversely the latter can be converted into the former by reactionwith one to four atomic Weights of sulphur for each molecular weight ofsaid unit.

It has been discovered that when the space between the adjacent carbonatoms in the is opened up and intervening structure inserted therebetween polymers of the unit -C @Simeare produced where represent carbonatoms separated by intervening structure.

As already stated, the reaction involving the use of an alkalinepolysulphide requires the selection of an organic compound having atleast two carbon atoms and a substituent attached to 'l' is interveningstructure between said reactive carbon atoms. That mechanism and thestructure of the polymers which may be produced by the specificpolysulphide or mercaptan reaction has been fully explained herein andit Will therefore be clear that whether or not there is interveningstructure between the reactive carbon atoms, the general formula of thepolymers is substantially [-RSZ to s-l where R has the carbon structurealready ex- All intervening structure between said reactive carbon atomsmodifies, however, the character of the polymers obtained, as comparedwith the polymers produced from compounds having no interveningstructure between said reactive carbon atoms and the present inventioninvolves the concept of providing intervening structure` between saidreactive carbon atoms and incorporating the resulting polymers withpolymerized butadiene.

As a result of the application of this concept, composite polymers canbe produced having a variety of special properties for special uses, asalready described. 'Ihe invention will be further described byillustrating the production and propertles of polymers of the unit wherethe intervening structure between the pair of reactive carbon atoms isselected from the following classes, it being understood that otherintervening structure may be employed:

Ether linkage Unsaturated carbon atoms Aromatic structureSaturated'stra'ight chain carbon atoms Saturated branched chain carbonatoms.

Where the intervening structure is 01 contains an ether linkage When thesaid pair of carbon atoms are joined to and separated by interveningatomic structure characterized by an ether linkage, certain importantadvantages are obtained. These advantages relate particularly to thepolymer in its final form, i. e., the form produced by incorporating thepolymer in its intermediate stage with polymerized butadiene and curingthe product. These advantages are in general characterized by acombination of the following prop- ,ertiesz elasticity, mechanicalstrength, retention of these properties at low ternperatures,`insolubility in common solvents and resistance to distortion by heat.

A specific example, for the purpose of illustration, of one method ofobtaining a polymer of the unit where represents two carbon atomsseparated by intervening structure characterized by an ether linkage isa reaction between BB dihalogenated ethyl ether and sodiumtetrasulphide. The polymer produced is substantially a polymer of theunit and this may be converted back from its disulphide form to thecorresponding polysulphide form by heating or reacting one mol of saidunit with one, two, three or four atomic weights of sulphur.

Moreover, a polymer of the unit oxidizing BB' dimercapto ethyl ether.The disulphide polymers have certain advantages over the polysulphidepolymers. e

The general formula for polymers of the unit represents carbonatomsiseparated by and ioined to structure characterized by an-etherlinkage is tai-SW1 where EXAMPLE 5 Into a closed reaction tank suitablyequipped with stirring means, pipe coils for steam and cold water and athermometer, are placed 2000 liters of 3-molar sodium tetrasulphidesolution. To the polysulphide solution are added with vigorousagitation, kilograms of caustic soda' dissolved in l5 liters of water.This is followed by the addition of kilograms of crystallized magneslumchloride (MgClzHzO) dissolve-d in 2'0 liters of Water.

The polysulphide mix is heated to about 135 F. and about 700 kilograms(5 kilogram mols of BB' dichlor ethyl ether are added gradually over aperiod of about three hours. The rate of addition of the dichloro etheris so regulated as to prevent the temperature of the reaction from goingabove about 210 F. during the reaction.

When all the chloro ether has been added and the temperature shows atendency to drop, steam may be admitted to the heating coils and soregulated as to maintain a temperature of from 215 to 220 F. for. aboutthree hours during which time the latex-like dispersion of the polymeris constantly stirred or agitated. The heating step just described iscarried out in order that the excess of polysulphide over that actuallyrequired to decompose the A dichloro ether may exert a condensing orpolymerizing eiect on the reaction p'roduct as first formed, asillustrated in Equation -F of the annexed drawing.-

' sion may now be used in the dispersed form or it may be separated fromexcess water by ltration and drying to give an elastic mass; or it maybe treated with suicient dilute acid, for example dilute hydrochloric,sulphuric or acetic acid, to confer a slight acidity on the latex-likedispersion, whereupon coagulation occurs. The coagulum can be freedyfrom adherent and occluded water by mastication or kneading on rollsor'by prolonged drying or byosubjecting to pressure.

- It will be noted that in the above example six kilogram mols of thepolysulphide were used whereas only about iive kilogram mols of theorganic reactant were used, leaving about 20 molar per cent excess ofthe polysulphide. This 'procedure provides an excess of polysulphideover that required ior decomposition of the organic compound' and thisexcess is available for the second step which results in furtherpolymerization of the product due to the oxidizing effect of the excesspolysulphide on the nely divided reaction product during theprolonged-heating period.

Equimolecular proportions of the'organic reactant could be used with thepolysulphide and after the saponiflcation is complete an additionaltreatment with more polysulphide could be made.

Table II CHa.CHX.O.CI-IX'.CH3

AA' disubstituted ethyl ether X.C2H4.O.C2H4.X'

BB' disubstituted ethyl ether v Y X.CH2.0.CH2.X' Disubstituted methylether X.C2H4O.C2H4.O.C2H4.X'

Disubstituted ethoxy ethyl ether X.C2H4.S.C2H4.X'

Disubstituted thio ethyl ether X.CH2.S.CH2.X

Disubstituted thio methyl ether l CH:

xcnaomalicmocmx' .v Disubstituted 1,3 methoxy, 2,2 dimethyl propane vX.CH2.CH2.CH2.O.CH2.O.CH2.CH2.CH2X' Disubstituted dipropyl formal X,CH2.CH2.O.CH2.O.CHz.CH2.X'

Disubstituted diethyl formal xcnzocmorhocui Disubstituted dimethoxyethane xcmonz.oOocmcvHex'- Disubstituted para diethoxy benzene 5xcmocnaonaocmx' Disubstituted dimethoxy ethane:com.CH2.cH2.s.cHi.cH2.cH2.x'

Disubstituted dipi'opyl thio ether xcm.cmoomcmx' Disubstituted diethylcarbonate xcmrnzdonacmccngx' Disubstituted glycol di'atate Disubstitutedtrimethylene glycol dipropionate y pp Disubstituted diphenyl ether'Disubsmuted anime Disubstituted dibenzyl ether x x' l I oo'Disubstituted diphenyl ether xGcmocm-@YCHLCHCHR Alt! Disubstituted parapropyl dibenzyl ether X.cH2'.cH2.so..cm.cH2.x'

Disubstituted diethyl sulphone X.CI-h.CH2.CH2.S'Oa.CHz.CHz.CH2X'Disubstituted dipropyl sulphone 0113.0.circHgo.omcm.ocmcmomoaocm x x'Disubstituted dimethoxy tetra ethylene glycol cmcmcaorlinmcm AA'disubstituted propyl ether cHmH?.CHLQCHLCHLCH, l le Gamma gammadisubstituted propyl ether cnacacmocmcucm A le x' BB' disubstitutedpropyl ether cmoncmocncnscnl l X, i Alpha beta disubstituted propylether cmcmcmoxlmmom x x' Alpha. gamma disubstituted propyl ethercri3.cH1.cH,.cH.o.clromcmcm Alpha alpha disubsttuted butyl etherCH3.CH2.(!H.CH2.O.CH:.(IJH.CHLCHx Beta beta disubstituted butyl ethercmorncm.cmocmcmcrrcm benzoyl peroxidn nd organic mono and polyv Gammagamma. disubstltuted butyl ether (lHaCHx.CHLCHLO.CHLCHLCHLHQ x x" Denadlta disubsutua butyl ether In some of the examples set forth in theabove list it will be noted that the substituents which' are split oil?are attached directly to an aromatic nucleus. The reaction is carriedoat-as in Example 1, except that the temperature is increa sed as, forexample, by'workng in an autoclave or bomb. The temperature necessarymay be illus-` trated by the fact that in the case of pp' dichlorodiphenyl ether, a temperature of about 500 F. for about one hour isnecessary.

The proportion of sulphur to the polymers produced from the abovecompounds varies from 20 to per cent, depending upon whether the sulphurin the unit is a group of two, three'four, ve or six sulphur 'l atomsand'alsodepending upon the molecular In the above cup there are foundformals. esters, ethers, thloethers, sulphones, alkoxy compounds andaryloxy compounds. In al1, however, there are two carbon ato ined to andseparated by structure charac bsaan ether linkage.. 'I'here is a. commonquality running through the entire series. To each of the said carbonatoms there is joined a substituentwhich is split oil. An ether linkageis defined as an oxygen or sulphur atom functioning as a link or bridgebetween two adjacent carbon atoms, thus R-O-R' or R.S.R' where R and Rare carbon atoms and structure characterized by an ether linkage in theoxygen or sulphur atom itself (or structure containing said oxygen orsulphur atom) functioning in thef manner described.

Owing to this commonlquality, the polymers produced from tlese compoundsby reaction with an alkaline polysulphide have a number of outstandingand important properties which distinguish them from the polymersproduced from disubstituted ethylene and propylene, as alreadydescribed. This is particularly true after the intermediate potentiallyreactive polymers have been cured and the curing step will beillustrated by Example 6.

Any oi' the polymersproduced by substituting any ofthe compounds inTable II for the BB' di'chloroethyl ether vof Example 5, may besubstituted in Commund B of Example 2, for incorporationwith'polymerized butadiene and subweight of the dirbstituted compound.

Vsequent curing of the compound'as set forth in said Example 2.

The -above ingredients are thoroughly mixed by mastication and then theresulting compound is cured by heating to about 300 F. for about onehour. Instead of zinc oxide other oxidizing agents can be used, e. g,oxides of copper, lead, bismuth, antimony, arsenic, manganese andchromium. O c oxidizing agents including nitro can also be used.

It has already been stated that the polymers of the unit B Rsn-l may beproduced not only.

by the alkaline polysulphide reaction-but also by oxidizing polymercaptocompounds. Al specific,

illustration will be given as follows:

EXAMPLE 7 SH.C2H4.O.C2H4.SH, are dissolved in 100 gallons sodiumhydroxide sodium hydroxide solution containing 90 lbs. of NaOH;\ thatis, an amount of NaOH slightly in excess of 2 mols. With this solutionthere is intimately mixed a freshly prepared suspension of magnesiumhydroxide made by treating lbs. of MgClzHzO with 2 gallons of water andadding thereto a solution of 4 lbs. NaOH dissolved in 0.5 gallon ofwater. The entire mixture isthen placed in a reaction vessel providedwith stirring means and also means for heating, for example, steamcoils. The mixture is subjected to stirring and to this is graduallyadded an oxidizing agent in the form of a solution of sodiurnvpolysulphide (made, for example, by dissolving 348 lbs. or 2 mols ofsodium tetrasulphide in 100 gallons of water) during a period of aboutten minutes. The reaction occurs approximately at room temperature andis somewhat exothermic. The reaction is substantially completed afterall the polysulphide has been added. The polysulphide acts as anoxidizing agent and converts the dimercapto ethyl ether into a complexpolymer'or plastic. The completion of the reaction is indicated bywithdrawing a sample, acidifying it and observing whether the odor ofmercaptan is absent. Stirring mayv nify -SH groups, can be substitutedfor the dimercapto ethyl ether.

'Ihe compounds so produced are substantially polymers of the unit[-RSz-l. 'I'hey may be produced not only as shown in Example 7, but

'also by removing the labile sulphur from the tetrasulphide polymerproduced as in Example 5. This will be speoically illustrated by thefollowing example:

y EXAMPLE 8 Proceed as in Example 5 up to but not including the step ofcoagulation. Add 250 kilograms (6.25 kilogram mols) of NaOH dissolved in500 litres of water, raise the temperature to 212 F. and maintain therefor about 30 minutes. Then cool, settle and proceed as in Example 5 towash the latex and coagulate the polymer. Instead of the specicsubstance used in Example 8, any of the disubstituted compoundsmentioned herein may be used, where X and X are substituents split oiduring the reaction, in the same molecular proportion.

Any of the polymers produced as in Examples 7 and 8 may be substitutedfor the -IRSz-l polymer usedin Examples 1 and 3 for incorporation withpolymerized butadiene.

Another class of polysulphide polymers particularly useful forincorporation with polymerized butadiene are polymers obtained byreacting polymer of the unit [-RSz-l with comand R have skeletonstructure selectedfrom the groups -a- 5 and I I I I l c n l'- I whererepresent adacent carbon atoms and I n u n l'- represent carbon atomsseparated by intervening structure, S isa sulphur atom and X and X aresubstituents split oif during the reaction. R and R may have the sameskeleton structure but preferably clierent specific structure. In thisway a polymer is obtained having different radi- AJcals R and R. in thesame molecule. This will .be illustrated by the following example. Inthis example the polymer is made from BB dichloro ethyl ether and saidpolymer is then reacted with ethylene dichloride. I Instead of thesespecific compounds, however, any of the disubstituted compounds listedherein may be substituted, different compounds being selected to makethe polymer and to react it as shown, after it is formed, so that thefinal compound will have different radicals R. and R' in the samemolecule.V

EXAMPLE 9 3000 liters of 2 molar sodium tetrasulphide solutioncontaining 6000 gram mols of Naas.; are treated with 8 kilograms of NaOHfollowed by 20 kilograms of MgCl26I-I2O in a reaction vessel as inExample '1. 6000 gram mols of BB' cli-chloroethyl ether are slowly addedduring about 3 hours and the temperature is maintained at about 160 F.with stirring, after which the temperature is raised to 200 F. and heldthere about 2 hours with agitation. The polymer formed is in the form ofa latex which is settled out. The supernatant liquor is drawn oft andthe volume restored-by adding water. Then add 6000 gram mols of NaOH andheat to about 200 F'. with constant agitation and hold there about 30minutes to effect a partial desulphurization and to activate the polymerby converting all -SH groups into -SNa groups. Then cool down to about130 F. and add 2000 gram mols of ethylene dichloride during about halfan hour, with stirand maintain there about half an hour.` The product isnow a coupled polymer, still in the Aform of a latex which is settledout from the supernatant liquor which is drawn off. The residual latexis washed twice with Water with intermediate settling and drawing oi ofthe wash Water.

The resulting coupled polymer contains both disulphide and tetrasulphdegroups of sulphur atoms and is subjected to a further desulphurizingtreatment to complete the conversion of the organic polysulphide to thedisulphide. It has been found advantageous to effect a partialdesulphurizing prior to coupling, followed by a completion of thedesulphurizing subsequent to coupling. The completion of thedesulphurizing may l ring. 'Ihen raise temperature to Iabout 200 F.

about 2009 F. and held there about an hour. The coupled polymer is stillin the form of a latex. It is settled, washed free from color bysuccessive washings, drawn oi into a separate vessel and coagulated byadding acid as in Example 1.

Having explained the advantages to be obtained inserting structurecharacterized by an ether linkage, between the carbon atoms in the andincorporating polymers of this unit with polymerized butadiene theinvention'will be further described by illustrating various other kindsor classes of intervening structure.

Intervemng structure characterized by- A speciiic example for thepurpose of illustration is a reaction between an alkaline polysulphideand 1,4 disubstituted butene 2 This reaction is specifically describedas follows:

EXAMPLE 10 Proceed as in Example 5, substituting 1,4 dichlorobutene 2for BB' dichlorethyl ether, in the same molecular proportions.

In the above example, instead of 1,4 dihalogenated butene 2, any memberselected from the following list can be employed, using the samemolecular proportions and any of the polymers so obtained can besubstituted for the polymer of Example 2, Compound B, for incorporationwith polymerized butadiene.

Table III In all of the above compounds there are two carbon atomsjoined to and separated by structure characterized by unsaturatedhydrocarbons.

This is a common quality running through the entire series. To each ofthe said carbon atoms there is joined a substituent which is spilt offduring the reaction.V

The compound produced as in Example 10 is substantially a polymer of theunit It can be partially desulphurized as taught in Example 8 andconverted into a compound which is substantially a polymer of the unitand the latter polymer can also be produced as taught in Example '7, i.e., by the mercaptan reaction, using 1,4 dimercapto butene, 2. Any ofthe compounds in the above Table III, Where X and X' are ,-SH groups,can be used 'instead of the dimercapto ethyl ether of Example 7 and the[-RSa-l polymers so obtained can be substituted for the specic [-RSz-lpolymers shown in Examples 1 and 3.

Intervem'ng structure characterized by saturated carbon atoms.-This isillustrated by the following compound:

X.CH'2.CH2.CH2.X'

Where X and X are substituents capable of being split off by reactionwith an alkaline polysulphide, this compound may be substituted for theether of Example 5 in the same molecular proportion. The resultingcompound is substantially a polymer of the unit It can be partiallydesulphurized as in Example 8 and converted into a compound which issubstantially a polymer of the unit This compound can also be producedby the mercaptan reaction as taught in Example 7.

The tri, tetra-, penta.- and hexasulphides of this group may besubstituted for the propylene tetrasulphide of Example 4, Compound B.One of the advantages of such polymers over those obtained fromcompounds like ethylene or propylene dichloride is freedom from thecharacteristic disagreeable odor of the latter.

Instead of the speciiic compound above mentioned others that may beemployed are as follows:

X. (CH2) 4.X

thus producing a series of compounds which are substantially polymers ofthe unit f [-(CHz) S2 to s-l where n is greater than 2.

Intervem'ng structure characterized by aromatic or aryl stracture.-Thisis illustrated by the following compound:

Where X and X are substituentscapable of being split off by reactionwith an alkaline polysulphide, this compound may be substituted for ythe ether of Example 5 in the same molecular proportion. The resultingcompound is substantially a polymer of the unit CHOCHQSQ It maybepartially desulphurized as in Example 8 and converted into a polymerwhich is substantially a polymer of the unit PROC-1 This compound lcanbe also obtained by the mercaptan reaction as taught in Example 7.

. hours.

atoms. This is illustrated by the following reaction:

Examen: .11

' To one liter of 2 molar sodium tetrasulphide add a suspension ofMUCH): made by dissolving 25V grams of crystallized magnesium chloridein 100 cc. water and adding a solution of 10 grams of NaOH in 50 cc.water. Add about one mol (150 grams) of para dichlor benzene. Place themixture in`an autoclave, preferably provided with a stirrer, and heat toabout 300 cc. for about Cool to roomtemperature and proceed further astaught in previous examples.

Instead of paraxylene dichloride or paradichlorbenzene, other compoundsmay be selected, as, for example, any of the following: For the reactionwith alkaline polysulphide, X and X are substituents capable of beingsplit off during said reaction. For the mercaptan reaction, X and X are-SH groups:

XI X@ Orthodisubstltuted benzene X'CH,

.Disubstituted ortho xylene XCHLCHQCHLCHLX' aa' Disubstitutednaphthalene bb Disubstituted naphthalene oHzX' 1,3 disubstitutedmesitylene Disubstituted 1,4 dimethyl naphthalene pp' Disubstituteddibenzyl l aa' Disubstituted anthracene xcmenOcHacncHacH Disubstitutedpara ethyl butyl benzene.

x.cin.om.cmo.cnaomcnscncmcn,

l v x' Disubstituted para hexyl propyl benzene In all of the aboveexamples there are two' carbon atoms joined to and separated by aromaticstructure or structure characterized by an aromatic or aryl group orgroups. l This is a common quality running through the entire series.

'I'he tri, tetra, pentaand hexasulphide polymers so obtained may besubstituted for the speciilc polymer used in Example 2,- Compound B andthe disulphide polymer may be substituted for that of Example 1 andExample 3, Compound A, respectively, for' incorporation with polymerizedbutadiene.

Enough illustration has been supplied to make apparent the profoundinfluence of the interven- -ing structure and to make apparent the factthat the invention is not limited to the particular classes specificallymentioned.

' As previously mentioned, the curing of the composite product of thisinvention is aided greatly by an oxidizing. agent, also by an organicvulcanization accelerator land an organic acid.

vInstead of an organic acid as such, a compound capable of yielding suchacid, e. g., a nitrile, may be used. Instead of an organic acid,inorganic acids or substances yielding such, e. g., halides The term apolymerized butadiene or aV polymerized diole includes polymerizedbutadiene per se, polymerized chloroprene, polymerized isoprene,polymerized methyl isoprene, etc.

Ihis application is a continuation-impart of my copending applicationled May 26, 1934Ser. No. 727,739, which in 'turn was copending with myapplication Ser. No. 627,470 (now United States Patent 1,962,460), ledAugust 4, 1932.

I claim:

1. A plastic comprising a substance which is substantially a polymer ofthe unit I c a represents carbon atoms joined to and separated byintervening structure and S is a sulphur Whevl'e atom, incorporated witha polymerized butadiene.

2. A plastic comprising a substance which is substantially a polymer oithe unit 3. A plastic comprising a substance which is substantially apolymer of the unit TL-aww] represents carbon atoms joined to andseparated by intervening structure and S is a sulphur atom, incorporatedwith a polymerized butadiene, a metallic oxide and an organicvulcanization accelerator.

4. A plastic comprising a substance which is substantiallya polymer ofthe unit I-w-M-I imirepresents carbon atoms joined to and separated byintervening structure and S is a sulphur atom, incorporated with apolymerized butadiene, a metallic oxide, an organic vulcanizationaccelerator and an organic acid.

5. A plastic comprising a substance which is substantially a polymer ofthe unit represents carbon atoms joined to and separated by structurecharacterized by an ether linkage and S is a sulphur atom, incorporatedwith a polymerized butadiene.

6. A plastic comprising a substance which is substantially a polymer ofthe unit represents carbon atoms joined to and separated by structurecharacterized by an ether linkage and S is a sulphur atom, incorporatedwith a' polymerized butadiene andan oxidizing agent.

7. A plastic comprising a substance which is substantially a polymer ofthe unit represents carbon atoms joined to and separated where whereWhere where where I by structure characterized by an ether linkage' andS is a sulphur atom, incorporated with a polymerized butadiene, ametallic oxide and an organic vulcanization accelerator.

8. A plastic comprising a substance which is substantially a polymer ofthe unit represents carbon atoms joined to and separated by structurecharacterized by an ether linkage and S is a sulphur atom, incorporatedwith a polymerized butadiene, a metallic oxide, an organic vulcanizationaccelerator and an organic acid.

9. A plastic comprising a substance substantially a polymer oi the unit.

where S is a sulphur atom, incorporated with a polymerized butadiene.

10. A plastic comprising a substance which is substantially `a polymerof the unit where S is a sulphur atom, incorporated with apolymerized'butadiene and an oxidizing agent. 11. A plastic comprising asubstance which is substantially a polymer of the unit.

where S is a sulphur atom, incorporated with a polymerized butadiene, ametallic oxide and an organic vulcanization accelerator.

l2. A plastic comprising a substance which is substantially a polymer ofthe unit where which is where S is a sulphur atom, incorporated withv apolymerized butadiene, a metallic oxide. an organic vulcanizationaccelerator and an organic acid.

13.A plastic comprising a substance which is substantially a polymer ofthe unit Hwa-SW1 represents carbon atoms joined to and separated bystructure characterized by x and S is a sulphur atout.v incorporatedwith a polymerized butadiene.

14. A plastic comprising a substance which is substantially a polymer ofthe unit represents carbon atoms joined to and sepa'- rated by structurecharacterized by and S is a sulphur atom, incorporated with apolymerized butadiene and an oxidizing agent.

where where 15. A plastic comprising a substance which substantially apolymer of the unit represents vcarbon atoms joined to and separated bystructure characterized by and S is a sulphur atom, incorporated with aI polymerized butadiene. a metallic oxide and an organicvulcanizationaccelerator.

1.6. A plastic comprising a substance which is substantially a polymer.of the unit f represents carbon atoms joined to and separated bystructure characterized by and S is a sulphur atom, incorporated with apolymerized butadiene, a metallic oxide, an organic vulcanizationaccelerator and an organic acid.

17., A plastic comprising a substance which is substantially a polymerof the unit represents carbon atoms joined to and separated by arylstructure and Sis a sulphur atom. incorporated with a polymerizedbutadiene. n

18. A plastic comprising a substance which is substantially a polymer ofthe unit 'v JIJ-SNMP] where where represents carbon atoms joined toandseparated by aryl structure and S is a sulphur atom, in-

corporated with a polymerized butadiene and an oxidizing agent.

19. A plastic comprising a substance which is substantially a, polymerof the unit represents carbon atoms joined to and separated by arylstructure and S is a sulphur atom, incorporated with a polymerizedbutadiene, a -metallic oxide and an organic vulcanization accelerator.

where 20. A plastic `comprising a substance which is substantially apolymer of the unit v H. im]

-i ...a I l represents carbon atoms joined to and separated byintervening structure and yS is a sulphur atom, incorporated with apolymerized butadiene.

22. A plastic comprising a substance which is substantially a, polymerof the unit te se] represents carbon atoms joined to and separated byintervening structure and S is a sulphur atom, incorporated with apolymerized butadiene and an oxidizing agent.

23. A plastic comprising a substance which is substantially a polymer ofthe unit where where where represents carbon atoms joined to andseparated' by intervening structure and S is a sulphur atom,incorporated with av polymerized butadiene, a metallic oxide and anorganic 'vulcanization accelerator.

24. A plastic comprising a substantially a polymer of the unit [ai-Selrepresents carbon atoms joined to and separated by intervening structureand S is a sulphur atom,

where incorporated with a polymerized butadiene, a metallic oxide, anorganic vulcanization accel' erator and an organic acid. v

25. A plastic comprising a substance which is substantially/a polymer ofthe unit represents carbon atoms joined to and separated where substancewhich is r by structure characterized by an ether linkage and S is asulphur atom, incorporated with a polymerized butadiene.

26. A plastic comprising a substance which is 4 substantially a polymerof the unit ima . l l represents carbon atoms joined to and separated bystructure characterized by and S is a sulphur atom, incorporated with a;polymerized butadiene.

where aman? 2'7. A plastic comprising a substance which is substantiallya polymer of the unit incorporated with a polymerized butadiene.

" JOSEPH C.PATRICK.

where

